Professor Richard Gregory died a few days ago. Richard carried out a great deal of work into the psychology of illusion, and his wonderful book, Eye and Brain, is responsible for sparking my interest in perception and deception. Early on in his career he came across a cafe in Bristol with a pattern of tiling that produced a striking illusion (details here), and so I thought it would be nice to use the image to produce a small tribute to the great man……
If you haven’t figured it out, the lines in the illusion appear sloping but are actually parallel.
Here is Richard in action explaining another wonderful illusion…..
Are you a fan of his work?
Richard Gregory was one of the three founders of AI at Edinburgh—now all gone. Richard didn’t stay in Edinburgh long, but his intellectual legacy persists.
He was my first scientific hero. Eye and Brain was my first introduction to the boundaries of the unknown in science—at school, science was absolute: all known and certain.
Gregory’s vision for the Exploratory in Bristol changed public engagement in Britain, and public perception of science—he changed the way we see the world.
I always looked forward to his periodic visits to Edinburgh. He continued to bring a new perspective and fresh excitement. To talk with him was a privilege and a joy.
Sadly missed.
There is a building in Melbourne, Australia which displays this illusion to great effect.

It is quite startling to look at in real-life, as it is more effective in 3D.
thanks – will put it on the blog!
Eye and Brain is still available as well http://www.amazon.com/Eye-Brain-Richard-L-Gregory/dp/0691048371
Have seen the building in Melbourne – it’s awesome. Did not know it was there and just sort of bumped into it (not literally!).
So cool that someone would build it.
There is a pub in Bristol tiled on the outside like that, and it makes me go squinty every time I walk past. I bet it’s even worse for all the people who have been in and had a pint or two…
Richard Gregory was one of the three founders of AI at Edinburgh—now all gone. Richard didn’t stay in Edinburgh long, but his intellectual legacy persists.
He was my first scientific hero. Eye and Brain was my first introduction to the boundaries of the unknown in science—at school, science was absolute: all known and certain.
Gregory’s vision for the Exploratory in Bristol changed public engagement in Britain, and public perception of science—he changed the way we see the world.
I always looked forward to his periodic visits to Edinburgh. He continued to bring a new perspective and fresh excitement. To talk with him was a privilege and a joy.
Sadly missed.
Street view of the cafe now:
http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&sll=51.457617,-2.597677&sspn=0.003336,0.009645&ie=UTF8&split=1&rq=1&ev=p&radius=0.25&hq=st+michael+hill&hnear=&t=h&layer=c&cbll=51.456961,-2.597532&panoid=OsQ8ktiSfq11TX20sJASmA&cbp=11,256.69,,0,4.4&ll=51.456962,-2.599586&spn=0.001511,0.009645&z=17
yes. yes i am.
The video actually made me a little seasick until I figured out the right perspective.
Love the checkboard illusion: so simple and yet so effective.
Was fortunate enough to have him as a guest lecturer in my first year at UWE. Had a brief conversation with him afterwards about the Charlie Chaplin illusion. A true gent, and saddened to hear of his passing.
I have a friend who is very crafty and loved this illusion, so she made a quilt of it:
http://www.flickr.com/photos/lydia_nichols/sets/72157623970917788/
when you keep pressing the up and down button to make the page shake it makes it really creppy
The tiles are still there at the bottom of St Michael’s Hill, and I enjoy the illusion every time I pass them. 🙂
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